package jd.d20211014.t1;

import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
 * @author habitplus
 * @since 2021-10-14 14:39
 */
public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
        String s = br.readLine();

        s = handle(s);
        System.out.println(s);

    }

    private static String handle(String s) {
        if (s == null ||s.length() == 0) {
            return "";
        }

        char[] chs = s.toCharArray();

        boolean[] d = new boolean[10];

        for (int i =0; i < chs.length; i++) {
            if (chs[i] >= '0' &&chs[i] <= '9') {
                d[chs[i] - '0'] = true;
            }
        }

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < d.length; i++) {
            if (d[i]) {
                sb.append((char)(i + '0'));
            }
        }

        return sb.toString();
    }
}
